Firms in the European countries today have the possibility of choosing from a range of control enhancing mechanisms giving the controlling owners an amount of influence which is disproportional to their share of cash flow. The list of control enhancing mechanisms includes dual class shares, pyramidal ownership structures and several others. The justification for these control enhancing mechanisms is currently the subject of much debate within the European Union. The opposing positions in the debate can be stated briefly as i) the control enhancing mechanisms are an impediment to takeovers and should therefore be removed to improve the market for corporate control. ii) Removing the control enhancing mechanisms reduces the contractual freedom to decide desirable ownership structures. This report investigates whether ownership structures affect firm performance. To do so this study provides a description of the current ownership structures in European countries and the economic outcomes for firms using different ownership structures. The results are presented in the tables below.